The present invention relates to a vehicle seat assembly and in particular to a seat assembly having a head rest vertically fixed in position with a vertically movable seat cushion and seat back. Regardless of the vertical position of the seat cushion and seat back, the head rest will remain in a predetermined position. Adjustment of the seat to place one's head in front of the head rest will result in placement of the occupant's eyes in the optimal position for visibility.
A seat assembly can be designed to vertically raise the seat cushion independently of the seat back or in conjunction with vertical movement of the seat back. If the seat cushion moves independently of the seat back, during adjustment the relative motion of the seat occupant with the seat back can cause discomfort and dishevel the seat occupant's clothing. Accordingly, it is often preferred that the seat back also be moved with the seat cushion.
Motor vehicles are typically designed with a particular line of sight for the seat occupant to have optimal vision both forward and rearward through a rear view mirror. To obtain the maximum benefit, the seat occupant must adjust the seat such that the occupant's eyes are at the optimum line of sight. The seat assembly, by having a vertically movable seat cushion enables the seat occupant to raise or lower his/her line of sight to the optimum position.